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Conference Spotlight
2025 ANS Winter Conference & Expo
November 8–12, 2025
Washington, DC|Washington Hilton
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The Standards Committee is responsible for the development and maintenance of voluntary consensus standards that address the design, analysis, and operation of components, systems, and facilities related to the application of nuclear science and technology. Find out What’s New, check out the Standards Store, or Get Involved today!
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Latest News
Japan gets new U for enrichment as global power and fuel plans grow
President Trump is in Japan today, with a visit with new Prime Minister Sanae Takaichi on the agenda. Takaichi, who took office just last week as Japan’s first female prime minister, has already spoken in favor of nuclear energy and of accelerating the restart of Japan’s long-shuttered power reactors, as Reuters and others have reported. Much of the uranium to power those reactors will be enriched at Japan’s lone enrichment facility—part of Japan Nuclear Fuel Ltd.’s Rokkasho fuel complex—which accepted its first delivery of fresh uranium hexafluoride (UF₆) in 11 years earlier this month.
J. Jedruch, R. J. Nodvik
Nuclear Technology | Volume 3 | Number 8 | August 1967 | Pages 507-518
Technical Paper and Note | doi.org/10.13182/NT67-A27783
Articles are hosted by Taylor and Francis Online.
The determination of the isotopic composition and the fission-product inventories of a spent reactor core is demonstrated through the proper selection of sampling points and analytical treatment of data using Core I of the Yankee reactor as an example. This core is found to contain 172 kg of 235U less than initially loaded, plus 97.0 kg of freshly generated Pu. Mass balances of U and Pu isotopes and the fission products are used to demonstrate the various possible ways of defining the end-of-life conversion ratio, with the preferred definition giving a value of 0.50 for the Yankee core. Methods of determining the total burnup from U and Pu concentrations, from 137Cs activity, and from plant calorimetrics are discussed and applied to the Yankee data and give 8.40 ± 0.21 GWD/MTU for the core average burnup.
